The present invention relates, generally, to distribution of secured prerecorded content and, in particular, to a method and an apparatus for enabling access, dependent upon timed availability, to the secured content provisioned on a storage medium,
It is known to distribution in bulk (i.e., mass distribution) software packages. Such packages generally comprise a software application in encrypted format on a CD-ROM which is distributed in advance to potential consumers who would either have none or limited use of the software application. Each consumer desiring full use or access thereto typically is required to place a voice call to a 1-800 number and purchase, via credit card, from the distributor a password (decryption) key that is capable of unlocking the encrypted software. A decryption utility which is supplied with the package and executed by the consumer on a personal computer prompts for the key, responsive to which the consumer enters the key and subsequently is allowed to copy the software application onto a disk. Alternatively, the software package may execute functionality to invoke an online connection, when the computer includes a modem, with an automated authorization center from which the key may be downloaded to the computer.
The above distribution technique is limited in its ability to generate revenue from the software package, specifically, to receipt of a single payment for unrestricted use of the software application.
In U.S. Pat. Nos. 4,827,508 to Shear and 5,010,571 to Katznelson, systems for metering access to encrypted data in the form of a database provisioned on a CD-ROM are disclosed. Briefly, in Shear or Katznelson, a CD-ROM containing an encrypted database of interest to a user is distributed typically at nominal cost or at no cost. The user terminal includes a CD-ROM reader, and a remote cryptographic control unit which is provided with stored cryptographic keys needed to access to the database. The amount of actual data use, i.e. the retrieval and decryption of data from the CD-ROM, is metered locally and recorded as a stored data usage record. The charge for data access may be either in accordance with the amount of data decrypted, or in accordance with price information recorded in the respective data headers of each individual data packet.
The local stored data usage record is reported by telephone modem from the remote user terminal to a cryptographic operations center. Each remote cryptographic control unit has a stored user secret key, unique to that user terminal. Communication between the user terminal and the cryptographic operations center is protected by encryption under the user secret key, which is stored in a secure memory in the cryptographic control unit. The user secret key for each user is also stored in the cryptographic operations center. When a remote user terminal calls in and identifies itself, the cryptographic operations center looks up the corresponding user secret cryptographic user key, which is then used to secure the subsequent communication data exchange between the remote user terminal and the cryptographic operations center. Also stored in the cryptographic operations center are the various cryptographic keys corresponding to the available CD-ROM database titles. The user secret key is also used to secure the delivery of secret database keys from the cryptographic operations center to the user terminal for a desired CD-ROM database. After the data usage report is successfully uploaded to the cryptographic operations center, the user is then billed for the actual database usage based on the content of the uploaded data usage report. Thus, rather than being required to purchase an entire CD-ROM database, the user pays only for the amount of data actually used or decrypted from the CD-ROM.
It is, therefore, apparent that more flexible and alternative capabilities to unlock secured prerecorded content whereby revenue generation from distribution thereof is expanded are desirable. Shear or Katznelson provide such capabilities on the basis of measuring actual use of the content. Capabilities based on timed availability to the secured content is a further alternative.